With recent rapid industrial development, the life environment has been contaminated and eating habits have changed, and thus various allergic diseases increased. Particularly, the incidence of asthma among such allergic diseases has greatly increased. Asthma is a lung disease characterized by chronic inflammation of the airways and airway hyperresponsiveness, and is caused by air pollutants, yellow sand, allergens, etc. It is known that the prevalence of asthma is higher in children than in adults and is increasing due to changes in eating habits and the Westernization of eating habits. It is known that mechanisms of development of asthma are very diverse. In such mechanisms, T helper type 2 (Th2) type immune responses, and thus the secretion of interluekin-4, 5 and 13, etc., increases, and together with such responses, many inflammatory cells, including neutrophils, migrate and infiltrate into lung tissue. In addition, numerous inflammatory cells release a variety of proinflammatory factors and chemotactic factors, which make inflammatory responses worse, increase mucus secretion from goblet cells in the airways, and cause airway hyperresponsiveness. Due to such a series of responses, asthma patients show clinical symptoms, including difficulty in breathing, cyanosis, and chest pain.
Drugs that are currently used for the treatment of asthma include steroidal agents, bronchodilators or antibiotics. Steroidal agents and antibiotics are used to treat asthma by inhibition of immune responses and inflammatory responses, and bronchodilators are used to offset clinical symptoms such as difficulty in breathing. However, such drugs cause side effects such as immune suppression and bone marrow suppression, antibiotic resistance, and also cause side effects when they are used over a long period of time, and thus the use of such drugs as asthma therapeutic agents is very limited. Accordingly, there has been a need for the development of a natural material or a new compound, which overcomes such side effects, is less toxic, and has excellent therapeutic effects.
EC-18, as a kind of monoacetyldiglyceride compounds, was separated or extracted from the natural deer antler. EC-18 is known to be hematopoiesis. Also, it is known that EC-18 increases survivability ratio of animals in sepsis animal model experiment using cecal-ligation-puncture, and shows no-toxicity in GLP (Good Laboratory Practice) toxicity test. However, the effect of monoacetyldiacylglycerol compounds including EC-18 is not known or disclosed in allergic asthma. Accordingly, the present inventors have made extensive efforts to develop an agent for treating asthma, which is derived from a natural material or is a new compound. As a result, the present inventors have found that a monoacetyldiacylglycerol compound reduces airway hyperresponsiveness and inhibits infiltration of inflammatory cells into bronchi, and thus can be effectively used for the prevention or treatment of asthma, thereby completing the present invention.